1. Field of the Invention
The present invention relates to a data processing device which can process a predetermined job by communicating with another data processing device, a data management method which is applicable to the data processing device, a storage medium which stores a computer-readable program for achieving the data management method, and the program itself.
2. Related Background Art
As the hardware constitution in the data processing device, an encryption circuit is set directly on the bus connected to the hard disk. Consequently, in a case where the data are stored in the hard disk, all the data pass the encryption circuit. Thus, even if the software of the data processing device is upgraded, or even if the hard disk is stolen, the safety of the data is guaranteed. Moreover, as described in Japanese Patent Application Laid-Open No. 2004-139163, in the case where the CPU of the printing device encrypts the data and then stores the encrypted data in the hard disk, even if the hard disk is stolen, the safety of the data is likewise guaranteed.
As described above, if all the data stored in the hard disk are encrypted, it is possible to guarantee the safety of these data even if the hard disk is stolen. However, even in such a constitution, there is a fear that the safety of the data degrades if both the hard disk and the encryption circuit are stolen.